The wealthy Republican businessman turned politician has already put $50 million of his own money into his campaign fund and has traveled at the campaign's expense. He released a video Monday saying he's won some and lost some, but he chooses "to fight" instead of throwing in the towel.

The first-term governor is considered among the most vulnerable incumbents nationwide. He's clashed with majority Democrats since he took office, including an unprecedented budget impasse that recently ended.

The video features Rauner riding a motorcycle. He reiterates campaign promises from his first run, including term limits.

The gubernatorial race could be the most expensive nationwide with Democratic candidates including billionaire businessman J.B. Pritzker.